Check Valve Structure for Use in Pump of Hydraulic Cylinder

ABSTRACT

A check valve for use in pump of hydraulic cylinder comprises a check valve including a tubular member disposed therein and having a sheath member received therein, a pump including a chamber provided in an output pipe thereof for receiving the check valve, wherein the tubular member is constructed in the form of a hollow cylinder and includes a sealing sleeve fitted therearound, and includes an oil seal mounted on the front end thereof for the engagement with a hollow screw element in the chamber; the sheath member is comprised of a hollow cap member, a first spring element, a ball, a hollow disc element which are placed into the tubular member in turn, and a second spring element. By using the disc element and the second spring element, the tubular member may be fixed in the chamber, and by way of the screw element, the tubular member is enclosed in the chamber.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a check valve, and more particularly to a check valve for use in pump of hydraulic cylinder that may prevent the hydraulic oil from leakage during the accelerated operation of the jack.

2. Description of the Prior Arts

Cylinder is an indispensable component provided in jacks due to its high bearing capacity, thus lifting objects easily. However, conventional cylinder had some disadvantages, such as poor operating stability, slow raising speed and the like. To overcome such defects, an improved cylinder provided with an air operated pump therein had been developed and applied in the related field.

Such an improved air-operated pump is utilize an inputted air pressure to actuate a piston (including spring element disposed therein and designed in an air venting and position returning manner), a stem member of the piston is in communication with an oil route of the cylinder so as to cause a pump effect, such that the cylinder may generate larger fluid pressure during the operation of the air operated pump for enhancing the operating speed. Thereby, the lifting speed of the jack may be improved. However, such a lifting speed still can be accelerated.

The present invention has arisen to mitigate and/or obviate the afore-described disadvantages.

SUMMARY OF THE INVENTION

The primary object of the present invention is to provide a check valve for use in pump of hydraulic cylinder that may prevent the hydraulic oil from leakage during the accelerated operation of the jack.

Another object of the present invention is to provide a check valve for use in pump of hydraulic cylinder that the sealing sleeve may be replaced by the ring element 113, thus saving the production cost.

In accordance with one aspect of the present invention, there is provided a check valve for use in pump of hydraulic cylinder comprising a check valve including a tubular member disposed therein and having a sheath member received therein, a pump including a chamber provided in an output pipe thereof for receiving the check valve, wherein

the tubular member is constructed in the form of a hollow cylinder and includes a sealing sleeve fitted therearound, and includes an oil seal mounted on the front end thereof for the engagement with a hollow screw element in the chamber;

the sheath member is comprised of a hollow cap member, a first spring element, a ball, a hollow disc element and a second spring element;

the hollow cap member, the first spring element, the ball and the disc element are placed into the tubular member in turn, and by using the disc element and the second spring element, the tubular member may be fixed in the chamber, thereafter, by way of the screw element, the tubular member is enclosed in the chamber, such that the front end of the tubular member is matingly engaged with the screw element by using the resilience of the second spring element through the disc element, the sealing sleeve corresponds to an air opening of the chamber, and the ball abuts against the disc element by means of the first spring element for achieving a checking purpose, thereby the pump may generate an air pressure to push the ball away and input the pressure into a cylinder, then after the air pressure in the cylinder of a jack is released, the tubular member is pushed to press against the second spring element, such that the tubular member disengages from the air opening, and then the air pressure permits to vent from the air opening for a quick pressure releasing purpose, thereafter, the second spring element biases the tubular member to return its initial position such that the air opening may be sealed once more, thus preventing the hydraulic oil from leakage during the accelerated operation of the jack.

The present invention will become more obvious from the following description when taken in connection with the accompanying drawings, which show, for purpose of illustrations only, the preferred embodiment in accordance with the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective diagram of a jack according to the present invention;

FIG. 2 is a cross sectional diagram of a pump according to the present invention

FIG. 3 is a perspective diagram illustrating the exploded components of a check valve for use in pump of hydraulic cylinder according to the present invention;

FIG. 4 is a perspective diagram illustrating the assembly of the check valve for use in pump of hydraulic cylinder according to the present invention;

FIG. 5 is a cross sectional diagram illustrating the check valve for use in pump of hydraulic cylinder of the present invention being associated with a pump;

FIG. 6 is a cross sectional diagram illustrating the check valve for use in pump of hydraulic cylinder of the present invention outputting an air pressure;

FIG. 7 is a cross sectional diagram illustrating the check valve for use in pump of hydraulic cylinder of the present invention venting the air pressure;

FIG. 8 is a cross sectional diagram illustrating the operation of the pump according to the present invention;

FIG. 9 is a cross sectional diagram illustrating a tubular member of the present invention being provided with one or more ring elements.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to FIGS. 1 and 2, a check valve for use in pump of hydraulic cylinder in accordance with the present invention comprises a check valve 1 including a tubular member 11 disposed therein and having a sheath member 12 received therein, a pump 2 including a chamber 21 provided in an output pipe thereof for receiving the check valve 1, wherein

the tubular member 11 is constructed in the form of a hollow cylinder and includes a sealing sleeve 111 fitted therearound, and includes an oil seal 112 mounted on the front end thereof for the engagement with a hollow screw element 22 in the chamber 21 (as shown in FIGS. 3 and 4);

the sheath member 12 is comprised of a hollow cap member 121, a first spring element 122, a ball 123, a hollow disc element 124 and a second spring element 125.

In assembly, the hollow cap member 121, the first spring element 122, the ball 123 and the disc element 124 are placed into the tubular member 11 in turn, and by using the disc element 124 and the second spring element 125, the tubular member 11 may be fixed in the chamber 21. Thereafter, by way of the screw element 22, the tubular member 11 is enclosed in the chamber 21, such that the front end of the tubular member 11 is matingly engaged with the screw element 22 by using the resilience of the second spring element 125 through the disc element 124, the sealing sleeve 111 corresponds to an air opening 23 of the chamber 21, and the ball 123 abuts against the disc element 124 by means of the first spring element 122 for achieving a checking purpose (as illustrated in FIG. 5).

In operation, the pump 2 is compressed by the inputted air to actuate a piston so as to generate an internal pressure for being inputted into the chamber 21 through the output pipe, hence the air pressure may pass through the disc element 124 to push the ball 123 away (as shown in FIG. 6, the air pressure is greater than the resilience of the first spring element 122). Thereafter, the air pressure may further pass through the cap member 121 and the tubular member 11 to lead into the tank of the cylinder 3 for auxiliary pressure by using the pipe, such that the jack allows to lift object (as illustrated in FIG. 8). On the contrary, if desiring to lower the object, the pressure in the jack is released and the air release switch of the jack is turned on for returning air back to the chamber 21, since the air pressure is pressed with respect to the front end of the tubular member 11 (as illustrated in FIG. 7), and the ball 123 and the disc member 124 in the tubular member 11 form a checking effect, the air pressure pushes the tubular member 11 to move for pressing against the second spring element 125, such that the tubular member 11 disengages from the air opening 23, and then the air pressure permits to vent from the air opening 23 for a quick pressure releasing purpose. Thereafter, the second spring element 125 biases the tubular member 11 to return the initial position such that the air opening 23 may be sealed once more, thereby preventing the hydraulic oil from leakage during the accelerated operation of the jack.

Furthermore, the sealing sleeve 111 may include radially enlarged bulges arranged at two ends thereof respectively for providing a preferred engagement in response to the chamber 21.

Likewise, the tubular member 11 may include one or more ring elements 113 directly disposed on the exterior thereof for obtaining the sealing purpose relative to the chamber 21 (as shown in FIG. 9) such that the sealing sleeve 111 may be replaced by the ring element 113, thus saving the production cost.

The invention is not limited to the above embodiment but various modifications thereof may be made. It will be understood by those skilled in the art that various changes in form and detail may made without departing from the scope and spirit of the present invention. 

1. A check valve for use in pump of hydraulic cylinder comprising: a check valve including a tubular member disposed therein and having a sheath member received therein, a pump including a chamber provided in an output pipe thereof for receiving said check valve, wherein said tubular member is constructed in the form of a hollow cylinder and includes a sealing sleeve fitted therearound, and includes an oil seal mounted on the front end thereof for the engagement with a hollow screw element in said chamber; said sheath member is comprised of a hollow cap member, a first spring element, a ball, a hollow disc element and a second spring element; said hollow cap member, said first spring element, said ball and said disc element are placed into said tubular member in turn, and by using said disc element and said second spring element, said tubular member may be fixed in said chamber, thereafter, by way of said screw element, said tubular member is enclosed in said chamber, such that the front end of said tubular member is matingly engaged with said screw element by using the resilience of said second spring element through said disc element, said sealing sleeve corresponds to an air opening of said chamber, and said ball abuts against said disc element by means of said first spring element for achieving a checking purpose, thereby said pump may generate an air pressure to push said ball away and input the pressure into a cylinder, then after the air pressure in said cylinder of a jack is released, said tubular member is pushed to press against said second spring element such that said tubular member disengages from said air opening, and then the air pressure permits to vent from said air opening for a quick pressure releasing purpose, thereafter, said second spring element biases said tubular member to return the initial position such that said air opening may be sealed once more, thereby preventing the hydraulic oil from leakage during the accelerated operation of the jack.
 2. The check valve for use in pump of hydraulic cylinder as claimed in claim 1, wherein said sealing sleeve may include radially enlarged bulges arranged at two ends thereof respectively for a preferred engagement in response to said chamber.
 3. The check valve for use in pump of hydraulic cylinder as claimed in claim 1, wherein said tubular member may include one or more ring elements directly disposed on the exterior thereof for a sealing purpose relative to said chamber. 